CN117810108A - Method and system for measuring square resistance of conductive film on wafer surface - Google Patents

Abstract

The application provides a method and a system for measuring square resistance of a conductive film on a wafer surface, comprising the following steps: determining at least one group of measurement coordinate points based on the design layout of the wafer, wherein the measurement coordinate points are positioned in a dicing street or a non-effective chip area in the design layout of the wafer; after the wafer is metallized on the front surface and placed on the resistance measuring machine, the resistance measuring machine performs front surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain the front surface film square resistance corresponding to each measurement coordinate point. When the four probes of the front film are measured, the probe head of the resistance measuring machine is pricked into the position corresponding to the measuring coordinate point, namely, the reserved cutting channel or the non-effective chip area is pricked into, so that the chip area is not damaged, and the yield of products is not affected.

Description

Method and system for measuring square resistance of conductive film on wafer surface

Technical Field

The application relates to the field of chips, in particular to a method and a system for measuring square resistance of a conductive film on a wafer surface.

Background

The semiconductor wafer manufacturing process mainly includes a front side metallization (router) process or a back side metallization (router) process, a PVD process such as vacuum evaporation, and the like, in which an electrically conductive thin film needs to be formed on one side of a wafer. The four-probe measurement method is widely applied to measurement of square block resistance Rs in various fields, and especially in the production and manufacture of semiconductor integrated circuit chips, the four-probe measurement is a necessary means for detection of related preparation processes of various conductive films.

The four probes are adopted to measure the sheet resistance of the film, the probes are required to be pricked into the sample, and the four probes are destructive to measure the sheet resistance of the film.

Disclosure of Invention

The present application is directed to a method and a system for measuring sheet resistance of a conductive film on a wafer surface, so as to at least partially improve the above-mentioned problems.

In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

in a first aspect, an embodiment of the present application provides a method for measuring square resistance of a conductive film on a wafer surface, where the method includes: determining at least one group of measurement coordinate points based on a design layout of a wafer, wherein the measurement coordinate points are positioned in a cutting channel or a non-effective chip area in the design layout of the wafer; after the wafer is metallized on the front surface and placed on a resistance measuring machine, the resistance measuring machine performs front surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain front surface film square resistance corresponding to each measurement coordinate point.

In a second aspect, embodiments of the present application provide a system for measuring sheet resistance of a conductive film on a wafer surface, the system comprising: the upper computer and the resistance measuring machine platform are in communication connection with the upper computer;

the upper computer is used for determining at least one group of measurement coordinate points based on the design layout of the wafer, wherein the measurement coordinate points are positioned in a cutting channel or a non-effective chip area in the design layout of the wafer;

after the wafer is metallized on the front surface and placed on a resistance measuring machine, the resistance measuring machine is used for measuring the front surface film four probes based on at least one group of measurement coordinate points so as to obtain the front surface film square resistance corresponding to each measurement coordinate point.

Compared with the prior art, the method and the system for measuring the square resistance of the conductive film on the surface of the wafer provided by the embodiment of the application comprise the following steps: determining at least one group of measurement coordinate points based on the design layout of the wafer, wherein the measurement coordinate points are positioned in a dicing street or a non-effective chip area in the design layout of the wafer; after the wafer is metallized on the front surface and placed on the resistance measuring machine, the resistance measuring machine performs front surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain the front surface film square resistance corresponding to each measurement coordinate point. When the four probes of the front film are measured, the probe head of the resistance measuring machine is pricked into the position corresponding to the measuring coordinate point, namely, the reserved cutting channel or the non-effective chip area is pricked into, so that the chip area is not damaged, and the yield of products is not affected.

In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting in scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a system for measuring sheet resistance of a conductive film on a wafer surface according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a wafer according to an embodiment of the present disclosure;

FIG. 3 is a schematic flow chart of a method for measuring sheet resistance of a conductive film on a wafer surface according to an embodiment of the present disclosure;

fig. 4 is a second flow chart of a method for measuring sheet resistance of a conductive film on a wafer surface according to an embodiment of the present application.

In the figure: 10-an upper computer; 20-resistance measuring machine.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only to distinguish the description, and are not to be construed as indicating or implying relative importance.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the description of the present application, it should be noted that, the terms "upper," "lower," "inner," "outer," and the like indicate an orientation or a positional relationship based on the orientation or the positional relationship shown in the drawings, or an orientation or a positional relationship conventionally put in use of the product of the application, merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

To achieve conductive sheet square resistance (also known as Rs) measurements and avoid damage to chips (also known as die) in wafers (also known as Wafer or silicon chips), alternative Control Wafer is used to monitor conductive sheet square resistance measurements. However, this approach has other drawbacks, as described in detail below.

(1) Because the Spter equipment is usually that only a corresponding Wafer is placed in each Chamber (film forming Control Chamber) for forming a film, the Control Wafer cannot feed back the film sheet resistance of a product in real time, and only indirectly feeds back the film thickness of the film formed by the product, whether the resistivity of the film material changes or not, and the like;

(2) control wafer is actually a SiOx (oxide layer) bearing wafer, whereas the volume product typically already has a more complete device stack structure. Therefore, even if the film materials are the same, the film sheet resistances with the same thickness are different in the results of measurement on the Control wafer and the measured product respectively;

(3) in order to meet the requirement of day monitor, the product cannot be measured, and the Control wafer needs to be measured repeatedly for a plurality of times, so that the cost of the Control wafer is increased.

In order to overcome the above problems, embodiments of the present application provide a system for measuring sheet resistance of a conductive film on a wafer surface. Referring to fig. 1, fig. 1 is a schematic structural diagram of a system for measuring sheet resistance of a conductive film on a wafer surface according to an embodiment of the present application.

As shown in fig. 1, the system for measuring the sheet resistance of the conductive film on the surface of the wafer comprises a host computer 10 and a resistance measuring machine 20, wherein the host computer 10 and the resistance measuring machine 20 (also called as Rs machines) are in communication connection through a wired or wireless communication network.

The upper computer 10 is configured to determine at least one set of measurement coordinate points based on a design layout of the wafer.

In the scheme of the application, the total number of the measurement coordinate points can be but not limited to 16, and more measurement coordinate points can be determined, so that the sheet resistance measurement of the wafer is more uniformly and comprehensively completed.

It should be noted that, the measurement coordinate point is located in a scribe line or a non-effective chip area in the design layout of the wafer, and when the probe head pierces the measurement coordinate point, the effective chip area on the wafer is not damaged.

Referring to fig. 2, fig. 2 is a schematic view of a wafer according to an embodiment of the present application. As shown in fig. 2, the wafer is designed to be circular, and the chip area on the wafer is designed to be square, so that an ineffective chip area (Die with incomplete shape and structure) exists at the edge of the wafer, and the ineffective chip area is scrapped in the subsequent processing process, so that the ineffective chip area is needled, the chip area on the wafer is not damaged, and the yield is not affected.

It should be noted that, in the subsequent processing, no metal exists at the dicing street, all sputtered metal films are etched during metal pattern etching, the dicing street is needled, and four probes of the front film are measured, so that the square resistance of the conductive film on the surface of the wafer can be obtained, and the pricked dicing street is etched during the subsequent processing (such as etching) without damaging the chip area on the wafer and affecting the yield.

In the wafer manufacturing process, front side metallization is required, and a sputtered deposited film, that is, a front side surface conductive film, is formed on the front side of the wafer, and at this time, it is required to determine whether the front side surface conductive film of the wafer is abnormal or not, which can be completed by the resistance measurement machine 20.

Optionally, after front side metallization of the wafer is completed, the probe head with the front side of the wafer facing the resistance measurement tool 20 is placed on the resistance measurement tool 20.

The resistance measuring machine 20 is used for performing four-probe measurement on the front film based on at least one group of measurement coordinate points, so as to obtain the square resistance of the front film corresponding to each measurement coordinate point.

In this application scheme, when carrying out four probe measurements of positive film, the probe head of resistance measurement board 20 pricks the position that measurement coordinate point corresponds, pricks reserved cutting way or non-effective chip area promptly, can not cause the destruction to the chip area, does not influence the yields of product.

For a specific procedure for front side film four probe measurement, the present examples also provide an alternative implementation, see below.

The resistance measurement machine 20 is configured to obtain each set of measurement coordinate points based on a pre-configured mapping relationship, and determine a corresponding probe coordinate point.

The pre-configured mapping relation is a mapping relation between a design layout coordinate system of the wafer and a probe coordinate system of the resistance measuring machine.

It should be noted that, the resistance measurement machine 20 may complete coordinate point matching through the pre-configured mapping relationship, determine each set of measurement coordinate points, and determine the corresponding probe coordinate points. The measuring coordinate points are coordinate points in a coordinate system of a design layout of the wafer, and the probe coordinate points are coordinate points in a probe coordinate system of the resistance measuring machine.

The resistance measuring machine 20 is used for controlling the probe head to be sequentially inserted into each group of probe coordinate points to perform four-probe measurement on the front film so as to obtain the front film square resistance corresponding to each measurement coordinate point.

Optionally, after the front film square resistance corresponding to each measurement coordinate point is obtained, determining the front film thickness corresponding to each measurement coordinate point according to the obtained front film square resistance and the corresponding resistivity, and further determining the actual film forming quality based on the front film thickness corresponding to each measurement coordinate point to determine whether the film is abnormal. Because the product is subjected to nondestructive testing, the product can be subjected to full inspection or multiple spot inspection under the condition of capacity permission, and the outflow of the product with abnormal film is reduced.

When it is determined that the surface conductive film on the front surface of the wafer is not abnormal, the subsequent process may be further performed on the surface conductive film, including: an exposure process, a development process, an etching process, and the like.

After the front surface of the wafer completes the subsequent process, the wafer manufacturing process is continued, the back surface of the wafer needs to be metallized, and a sputtering deposition film, that is, a surface conductive film on the back surface of the wafer needs to be formed, and at this time, whether the surface conductive film on the back surface of the wafer is abnormal or not needs to be judged, and the process can be completed through the resistance measuring machine 20.

Optionally, after the wafer is back metallized, the probe head with the back side of the wafer facing the resistance measurement tool 20 is placed on the resistance measurement tool 20.

The resistance measuring machine 20 is further configured to perform four-probe measurement on the back film based on at least one set of measurement coordinate points, so as to obtain a back film sheet resistance corresponding to each measurement coordinate point.

In this application scheme, when carrying out four probe measurements of back film, the probe head of resistance measurement board 20 pricks the position that measurement coordinate point corresponds, pricks reserved cutting way or non-effective chip area promptly, can not cause the destruction to the chip area, does not influence the yields of product.

For a specific procedure for back side film four probe measurement, the present examples also provide an alternative implementation, see below.

The resistance measurement machine 20 is configured to obtain each set of measurement coordinate points based on a pre-configured mapping relationship, and determine a corresponding probe coordinate point.

The pre-configured mapping relation is a mapping relation between a design layout coordinate system of the wafer and a probe coordinate system of the resistance measuring machine.

The resistance measuring machine 20 is used for controlling the probe head to be sequentially inserted into each group of probe coordinate points to perform back film four-probe measurement so as to obtain back film square resistance corresponding to each measurement coordinate point.

Optionally, after the back film square resistance corresponding to each measurement coordinate point is obtained, determining the back film thickness corresponding to each measurement coordinate point according to the obtained back film square resistance and the corresponding resistivity, and further determining the actual film forming quality based on the back film thickness corresponding to each measurement coordinate point, so as to determine whether the film abnormality exists. Because the product is subjected to nondestructive testing, the product can be subjected to full inspection or multiple spot inspection under the condition of capacity permission, and the outflow of the product with abnormal film is reduced.

Based on the foregoing, the embodiment of the present application further provides an optional implementation, please refer to the following, regarding how the upper computer determines at least one set of measurement coordinate points based on the design layout of the wafer.

The upper computer 10 is configured to determine an intersection point of any two intersecting cutting lanes as a measurement coordinate point, or select a preset number of measurement coordinate points that are uniformly distributed from the intersection points of all the intersecting cutting lanes according to a preset length interval.

Based on the foregoing, the embodiment of the present application further provides an optional implementation, please refer to the following, regarding how the upper computer determines at least one set of measurement coordinate points based on the design layout of the wafer.

The upper computer 10 is used for drawing circles based on the center point of the design layout of the wafer and at least two groups of preset radiuses.

Optionally, N groups of preset radiuses are shared, and N is more than or equal to 3; the difference between the i+1th group preset radius and the i th group preset radius is equal to the preset distance interval, i is more than or equal to 1 and less than or equal to N-1, and the preset distance interval can be equal to the 1 st group preset radius.

The upper computer 10 is used for determining corresponding measurement coordinate points on each circle according to the preset arc length interval.

It should be noted that, through the preset arc length interval, the equal interval distribution of the measurement coordinates on the same circle is ensured, and more measurement coordinate points corresponding to the circle with a large radius can be ensured, so that all measurement coordinate points are uniformly distributed in the wafer, and the accuracy of the final measurement result is ensured.

With respect to determining corresponding measurement coordinate points on each circle at preset arc length intervals, the embodiments of the present application also provide an alternative implementation, please refer to the following.

The 1 st measurement coordinate point on the circle is determined.

Optionally, a point of a scribe line or a non-effective chip area located in the design layout of the wafer on one circle is randomly designated as the 1 st measurement coordinate point.

And determining the 1 st suspected point in the preset direction of the 1 st measurement coordinate point, wherein the distance between the 1 st suspected point and the 1 st measurement coordinate point is equal to the preset arc length interval, and the 1 st suspected point is positioned on the circle.

Alternatively, the preset direction may be a clockwise direction or a counterclockwise direction, which is not limited herein.

And determining whether the 1 st suspected point is positioned in a cutting path or a non-effective chip area in the design layout of the wafer.

And if the 1 st suspected point is positioned in a cutting path or a non-effective chip area in the design layout of the wafer, determining the 1 st suspected point as the 2 nd measuring coordinate point on the circle.

If the 1 st suspected point is not located in the cutting channel or the non-effective chip area in the design layout of the wafer, determining the point position of the cutting channel or the non-effective chip area, which is located in the design layout of the wafer, on the circle to be closest to the 1 st suspected point as the 2 nd measurement coordinate point on the circle.

Let k=2.

And determining a kth suspected point in the preset direction of the kth-1 suspected point, wherein the distance (arc length distance) between the kth suspected point and the kth-1 suspected point is equal to the preset arc length interval, and the kth suspected point is positioned on the circle.

And determining whether the kth suspected point is located in a scribe line or a non-valid chip area in the design layout of the wafer.

If so, the kth suspected point is determined to be the kth+1th measurement coordinate point on the circle.

If not, determining the point position of the cutting path or the non-effective chip area on the circle, which is closest to the kth suspected point, in the design layout of the wafer as the kth+1th measurement coordinate point on the circle.

Let k=k+1, determine whether k is smaller than the judgment threshold corresponding to the circle.

Optionally, the value of the judgment threshold is matched with the radius of the circle and the preset arc length interval, the judgment threshold is set so that the last measurement coordinate point is located at one side of the 1 st measurement coordinate point far away from the 2 nd measurement coordinate point, and the distance between the last measurement coordinate point and the 1 st measurement coordinate point is smaller than or equal to 1.5 times of the preset arc length interval and is larger than 0.5 times of the preset arc length interval.

If k is smaller than the judgment threshold, the k suspected point is repeatedly determined in the preset direction of the k-1 suspected point until k is larger than or equal to the judgment threshold, and the process is finished, and the process can be repeatedly started to determine the measurement coordinate point on the next circle.

It should be understood that the configuration shown in fig. 1 is only a schematic diagram of a portion of a wafer surface conductive film sheet resistance measurement system, which may also include more or fewer components than shown in fig. 1, or have a different configuration than shown in fig. 1. The components shown in fig. 1 may be implemented in hardware, software, or a combination thereof. The host computer 10 in fig. 1 may be, but is not limited to, a mobile phone, a computer, a server, etc.

The method for measuring the sheet resistance of the conductive film on the surface of the wafer provided in the embodiment of the present application may be applied to, but not limited to, the system for measuring the sheet resistance of the conductive film on the surface of the wafer shown in fig. 1, and referring to fig. 3, the method for measuring the sheet resistance of the conductive film on the surface of the wafer includes: s100 and S200 are specifically described below.

S100, determining at least one group of measurement coordinate points based on the design layout of the wafer.

The measuring coordinate points are located in cutting tracks or non-effective chip areas in the design layout of the wafer.

And S200, after the wafer is metallized on the front surface and placed on a resistance measuring machine, the resistance measuring machine performs front surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain the front surface film square resistance corresponding to each measurement coordinate point.

In S200, after obtaining the front sheet resistance corresponding to each measurement coordinate point, the embodiment of the present application further provides an alternative implementation, referring to fig. 4, and the method for measuring the sheet resistance of the conductive sheet on the wafer surface further includes: s300 is specifically described below.

S300, after the wafer is metallized on the back surface and placed on a resistance measuring machine, the resistance measuring machine performs back surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain back surface film square resistance corresponding to each measurement coordinate point.

The embodiment of the present application further provides an alternative implementation, with respect to the content in S100, based on fig. 3, please refer to the following. S100, determining at least one group of measurement coordinate points based on a design layout of a wafer, wherein the method comprises the following steps: s110 and S120 are specifically described below.

S110, drawing circles based on the center point of the wafer design layout and at least two groups of preset radiuses.

Optionally, N groups of preset radiuses are shared, and N is more than or equal to 3; wherein the difference between the preset radius of the (i+1) th group and the preset radius of the (i) th group is equal to the preset distance interval, i is more than or equal to 1 and less than or equal to N-1.

S120, corresponding measurement coordinate points are determined on each circle according to the preset arc length interval.

Regarding the content in S120, the embodiment of the present application further provides an alternative implementation, please refer to the following. S120, determining corresponding measurement coordinate points on each circle according to preset arc length intervals, wherein the step comprises the following steps: s120-1 to S120-11 are specifically described below.

S120-1, determining the 1 st measuring coordinate point on the circle.

S120-2, determining the 1 st suspected point in the preset direction of the 1 st measurement coordinate point.

The distance between the 1 st suspected point and the 1 st measurement coordinate point (the radian distance on the circle) is equal to the preset arc length interval, and the 1 st suspected point is located on the circle.

S120-3, determining whether the 1 st suspected point is located in a scribe line or a non-effective chip area in the design layout of the wafer. If yes, executing S120-4; if not, S120-5 is performed.

S120-4, determining the 1 st suspected point as the 2 nd measurement coordinate point on the circle.

S120-5, determining the point position of the cutting path or the non-effective chip area, which is closest to the 1 st suspected point and is positioned in the design layout of the wafer, on the circle as the 2 nd measuring coordinate point on the circle.

S120-6, let k=2.

S120-7, determining the kth suspected point in the preset direction of the kth-1 suspected point.

The distance between the kth suspected point and the kth-1 suspected point (the radian distance on the circle) is equal to the preset arc length interval, and the kth suspected point is located on the circle.

S120-8, determining whether the kth suspected point is located in a scribe line or a non-valid chip area in the design layout of the wafer. If yes, executing S120-9; if not, S120-10 is performed.

And S120-9, determining the kth suspected point as the kth+1th measurement coordinate point on the circle.

S120-10, determining the point position of a cutting path or a non-effective chip area, which is closest to the kth suspected point and is positioned in the design layout of the wafer, on the circle as the kth+1th measurement coordinate point on the circle.

And S120-11, let k=k+1, and determining whether k is smaller than a judgment threshold corresponding to the circle. If k is smaller than the judgment threshold, repeating S120-7, determining the kth suspected point in the preset direction of the kth suspected point-1 until k is larger than or equal to the judgment threshold, and ending.

The embodiment of the present application further provides an alternative implementation, with respect to the content in S200, based on fig. 3, please refer to the following. S200, the resistance measuring machine performs four-probe measurement on the front film based on at least one group of measurement coordinate points to obtain the square resistance of the front film corresponding to each measurement coordinate point, and the method comprises the following steps: s210 and S220 are specifically described below.

S210, the resistance measuring machine obtains each group of measuring coordinate points to determine corresponding probe coordinate points based on a pre-configured mapping relation.

The pre-configured mapping relation is a mapping relation between a design layout coordinate system of the wafer and a probe coordinate system of the resistance measuring machine.

S220, the resistance measuring machine controls the probe head to be sequentially inserted into each group of probe coordinate points, and front film four-probe measurement is carried out, so that front film square resistance corresponding to each measurement coordinate point is obtained.

The embodiment of the present application further provides an alternative implementation, with respect to the content in S300, based on fig. 4, please refer to the following. S300, the resistance measuring machine performs four-probe measurement on the back film based on at least one group of measurement coordinate points to obtain the square resistance of the back film corresponding to each measurement coordinate point, and the method comprises the following steps: s310 and S320 are specifically described below.

S310, the resistance measuring machine obtains each group of measuring coordinate points to determine corresponding probe coordinate points based on a pre-configured mapping relation.

The pre-configured mapping relation is a mapping relation between a design layout coordinate system of the wafer and a probe coordinate system of the resistance measuring machine.

S320, the resistance measuring machine controls the probe head to be sequentially inserted into each group of probe coordinate points, and back film four-probe measurement is carried out, so that back film square resistance corresponding to each measurement coordinate point is obtained.

Note that when coordinate point matching is required, both S310 and S210 may be performed only one of them.

It should be noted that, the method for measuring the square resistance of the conductive film on the surface of the wafer provided in this embodiment may perform the functional use shown in the embodiment of the system for measuring the square resistance of the conductive film on the surface of the wafer, so as to achieve the corresponding technical effect. For a brief description, reference is made to the corresponding parts of the above embodiments, where this embodiment is not mentioned.

In summary, the method and system for measuring square resistance of a conductive film on a wafer surface provided in the embodiments of the present application include: determining at least one group of measurement coordinate points based on the design layout of the wafer, wherein the measurement coordinate points are positioned in a dicing street or a non-effective chip area in the design layout of the wafer; after the wafer is metallized on the front surface and placed on the resistance measuring machine, the resistance measuring machine performs front surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain the front surface film square resistance corresponding to each measurement coordinate point. When the four probes of the front film are measured, the probe head of the resistance measuring machine is pricked into the position corresponding to the measuring coordinate point, namely, the reserved cutting channel or the non-effective chip area is pricked into, so that the chip area is not damaged, and the yield of products is not affected.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

It will be evident to those skilled in the art that the present application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (10)

1. The method for measuring the square resistance of the conductive film on the surface of the wafer is characterized by comprising the following steps of:

determining at least one group of measurement coordinate points based on a design layout of a wafer, wherein the measurement coordinate points are positioned in a cutting channel or a non-effective chip area in the design layout of the wafer;

after the wafer is metallized on the front surface and placed on a resistance measuring machine, the resistance measuring machine performs front surface film four-probe measurement based on at least one group of measurement coordinate points so as to obtain front surface film square resistance corresponding to each measurement coordinate point.

2. The method for measuring sheet resistance of conductive film on a wafer surface according to claim 1, wherein after obtaining the sheet resistance of the front surface corresponding to each measurement coordinate point, the method further comprises:

after the wafer is metallized on the back and placed on a resistance measuring machine, the resistance measuring machine performs back film four-probe measurement based on the at least one group of measurement coordinate points so as to obtain back film square resistance corresponding to each measurement coordinate point.

3. The method for measuring sheet resistance of a conductive film on a wafer surface according to claim 1, wherein the step of determining at least one set of measurement coordinate points based on a design layout of the wafer comprises:

drawing a circle based on a center point of the design layout of the wafer and at least two groups of preset radiuses;

and determining corresponding measurement coordinate points on each circle according to the preset arc length interval.

4. The method for measuring sheet resistance of conductive film on wafer surface as claimed in claim 3, wherein the step of determining corresponding measurement coordinate points on each circle at predetermined arc length intervals comprises:

determining a 1 st measurement coordinate point on the circle;

determining a 1 st suspected point in a preset direction of the 1 st measurement coordinate point, wherein the distance between the 1 st suspected point and the 1 st measurement coordinate point is equal to the preset arc length interval, and the 1 st suspected point is positioned on the circle;

determining whether the 1 st suspected point is positioned in a scribe line or a non-effective chip area in the design layout of the wafer;

if yes, determining the 1 st suspected point as a 2 nd measurement coordinate point on the circle;

if not, determining the point position of a cutting path or a non-effective chip area in the design layout of the wafer, which is closest to the 1 st suspected point, on the circle as the 2 nd measurement coordinate point on the circle;

let k=2;

determining a kth suspected point in a preset direction of the kth-1 suspected point, wherein the distance between the kth suspected point and the kth suspected point is equal to the preset arc length interval, and the kth suspected point is positioned on the circle;

determining whether the kth suspected point is positioned in a scribe line or a non-effective chip area in the design layout of the wafer;

if yes, the kth suspected point is determined to be the kth+1th measurement coordinate point on the circle;

if not, determining the point position of a cutting path or a non-effective chip area in the design layout of the wafer, which is closest to the kth suspected point, on the circle as the kth+1th measurement coordinate point on the circle;

let k=k+1, determine whether k is smaller than the judgment threshold corresponding to the circle;

if k is smaller than the judgment threshold, repeating to determine the kth suspected point in the preset direction of the kth-1 suspected point until k is larger than or equal to the judgment threshold.

5. The method for measuring square resistance of conductive film on wafer surface according to claim 3, wherein N groups of preset radiuses are provided, and N is more than or equal to 3;

wherein the difference between the preset radius of the (i+1) th group and the preset radius of the (i) th group is equal to the preset distance interval, i is more than or equal to 1 and less than or equal to N-1.

6. The method for measuring sheet resistance of conductive film on wafer surface according to claim 1, wherein the step of measuring four probes of front surface film based on the at least one set of measurement coordinate points by the resistance measuring machine to obtain the sheet resistance of front surface film corresponding to each measurement coordinate point comprises:

the resistance measurement machine table obtains each group of measurement coordinate points to determine corresponding probe coordinate points based on a pre-configured mapping relation, wherein the pre-configured mapping relation is a mapping relation between a design layout coordinate system of the wafer and a probe coordinate system of the resistance measurement machine table;

the resistance measuring machine controls the probe head to be sequentially inserted into each group of probe coordinate points, and front film four-probe measurement is carried out, so that front film square resistance corresponding to each measurement coordinate point is obtained.

7. The method for measuring sheet resistance of conductive film on wafer surface as set forth in claim 2, wherein the step of measuring four probes of the back surface film based on the at least one set of measurement coordinate points by the resistance measuring machine to obtain the sheet resistance of the back surface film corresponding to each measurement coordinate point comprises:

the resistance measurement machine table obtains each group of measurement coordinate points to determine corresponding probe coordinate points based on a pre-configured mapping relation, wherein the pre-configured mapping relation is a mapping relation between a design layout coordinate system of the wafer and a probe coordinate system of the resistance measurement machine table;

and the resistance measuring machine controls the probe head to be sequentially inserted into each group of probe coordinate points, and back film four-probe measurement is performed so as to obtain the back film square resistance corresponding to each measurement coordinate point.

8. A system for measuring sheet resistance of a conductive film on a wafer surface, the system comprising: the upper computer and the resistance measuring machine platform are in communication connection with the upper computer;

the upper computer is used for determining at least one group of measurement coordinate points based on the design layout of the wafer, wherein the measurement coordinate points are positioned in a cutting channel or a non-effective chip area in the design layout of the wafer;

after the wafer is metallized on the front surface and placed on a resistance measuring machine, the resistance measuring machine is used for measuring the front surface film four probes based on at least one group of measurement coordinate points so as to obtain the front surface film square resistance corresponding to each measurement coordinate point.

9. The system of claim 8, wherein after the wafer is back metallized and placed on a resistance measurement tool, the resistance measurement tool is further configured to perform back film four-probe measurements based on the at least one set of measurement coordinate points to obtain a back film sheet resistance corresponding to each measurement coordinate point.

10. The system for measuring sheet resistance of a conductive film on a wafer surface as recited in claim 8, wherein the determining at least one set of measurement coordinate points based on the wafer design layout comprises:

drawing a circle based on a center point of the design layout of the wafer and at least two groups of preset radiuses;

and determining corresponding measurement coordinate points on each circle according to the preset arc length interval.